plan = [
    [2000.0, 2000.0, 2000.0, 2000.0, 2000.0, 2000.0],
    [2000.0, 2000.0, 2000.0, 2000.0, 2000.0, 2000.0, 2000.0],
    [2000.0, 2000.0, 1250.0, 1250.0, 1250.0, 1250.0, 1250.0],
    [1250.0, 1250.0, 1250.0, 1250.0, 1250.0, 1250.0, 1250.0],
    [1250.0, 1250.0, 1250.0]
]
 
from itertools import zip_longest
 
def formata(n, casas_decimais):
    try:
        return f'{float(n):.{casas_decimais}f}'
    except ValueError:
        return n
 
tamanho = 15
# o "size" na string abaixo é substituído pelo valor da variável "tamanho"
print(('{:<{size}}' * len(plan)).format(*map(lambda x: f'{x + 1}º PERÍODO', range(len(plan))), size=tamanho))
# mas dentro de uma f-string tem que ser a própria variável
print(f'{"1º PERÍODO":<{tamanho}}{"2º PERÍODO":<{tamanho}}{"3º PERÍODO":<{tamanho}}{"4º PERÍODO":<{tamanho}}{"5º PERÍODO":<{tamanho}}')
 
for metas in zip_longest(*plan, fillvalue=''):
    print(('{:<{size}}' * len(metas)).format(*map(lambda x: formata(x, 2), metas), size=tamanho))

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